Flat knitting machine



Jan. 16, 1940. H 5 AL 2,186,971

' FLAT KNITTING MACHINE Filed March 8, 1938 5 Sheets-Sheet 1 .5. Hart 32 15271351 Hie/Beer Jan. 16, 1940. 7 Q HERB AL 2,186,971

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FLAT KNITTING MACHINE Filed March 8, 1938 5 Sheets-Sheet 4 .Zaray Herb= fibbara ff. 51.715862?" Jan. 16, 1940- 1.. B. HERB El AL 2,136,971

FLAT KNITTING momma Filed March a, 1938 5 Sheets-Sheet s Hi a 1 687 I 5'4 12; I

wuem/tom lax-'09 ear-1Z7 Richard H S's/Seer Patented Jan. 16, 1940 UNITED STATES PATENT OFFICE FLAT KNITTING MACHINE Pennsylvania Application March 8, 1938, Serial'No. 194,684

7 Claims.

This invention relates to improvements in full fashioned hosiery knitting machines. I

It has for one of its objects the provision of means for integrally knitting courses of covered rubber thread into the stocking in such manner as to lay the maximum of thread into each course and with the least tension.

Another object of the invention is to provide means in a flat knitting machine to drop stitches 7 from the picot points at predetermined courses in the progress of the knitting. .This is particularly useful .in forming the elastic strain absorbing zones or bands in full fashioned stockings such as are described in the patents to Richard H. Scheer No. 2,102,486 and to Leroy B. Herb No. 2,079,738 and in the application for patent to Leroy B. Herb Serial No. 117,399, filed Decem ber 23, 1936.

A further object of the invention is to provide a machine for automatically laying in courses of any special thread including elastic thread in knitting fabrics generally, with reduction or absence of tension, and to form drop stitches in predetermined courses in knitting fabrics generally, during the progress of the knitting.

Other objects of the invention will appear as the following description of a preferred and practical-embodiment thereof proceeds. In the drawings which accompany and form a 30 part of the following specification and throughout" the several figures of which the same characters of reference have been employed to designate identical parts:

Figure 1 is a front elevation of so much of a full fashioned knitting machine as is essential to illustrate the present invention;

Figure 2 is a section taken along the line 2--2 of Figure 1;

Figure 3 is a perspective view illustrating the tension-relieving mechanism;

Figure 4 is a perspectiveview of that portion of the machine showing the drop stitch mechanism;

Figure 5 is a cross section taken along the line 5-5 of Figure 1;

Figure 6 is a' plan view partly in section showing the drop stitch mechanism; and- Figures '7, 8 and 9 are detail views illustrating successive positions of the needle and picot point.

In the making of full fashioned stockings it is desirable to integrally knit a sufficient number of courses of covered rubber yarn into the stocking above the knee to take the entire stretch to which the stocking is subjected when the knee is bent instead of requiring that the strain be borne by the relatively inelastic body portion of the stocking. By the provision of such means the stocking is rendered at least run-resistant and generaly run-proof. The greater the amount of elastic ruber thread that can be gotten into 5 each course of the elastic knitting, the greater will be the reservoir of elasticity which is drawn upon in the stretching of the stocking.

Unfortunately the knitting in of the covered rubber thread on machines as constructed prior 10 to the present invention has involved tensioning the rubber thread between the spool from which it is supplied to the machine and the yarn carrier so that it goes into the knitting in stretched condition. This causes a minimum amount of 16 elastic thread to go into each course and it also creates a tendency, for the elastic zone or band which constitutes the strain absorber to curl when the elastic thread releases or shortens in the knitted fabric. 2

The present invention seeks to obviate both of these undesirable features by supplying the elastic thread to the yarn carrier in a completely relaxed or untensioned condition.

Referring now in detail to the several figures 25 in which onlyso much of a conventional full fashioned knitting machine is shown as is necessary to illustrate the present invention, and first adverting to the mechanism which relieves the yarn of tension, this is best shown in Figures 1, 30 2 and 3 in which the numeral l represents the spool of special yarn and 2 the carrier which presents the special yarn to the needles of the needle bar 44, see Figure 1. The tension-relieving means comprises an arm 4 fixed to a shaft 5. 35

The shaft 5 is oscillatably mounted longitudinally of the knitting machine and the arm 4 oscillates in a vertical plane. There are as many arms 4 as there are needle bars. I L

The special yarn passes from the spool I 40 through an eye 6 at the end of the arm 4 and through a guide 1 on the arm 4 adjacent its free end. The special yarn adjacent the carrier 2 is incorporated in the knitting and: therefore may be considered anchored at this end. The '45 arm 4 has such length and such amplitude of oscillation that when it swings upward as shown in the position in Figure 3, it withdraws a length of yarn from the spool l equal to the amount that can be fed to the needle bar by'the carrier 2. This length of yarn and all the yarn between it and the carrier willthus be relieved from the tension automatically required in unreeling the yarn from the spool.

The oscillation of the arm 4 is so timed that M it makes its complete upward swing in the short period of pause which the carrier 2 makes at each end of the needle bar. It makes its return or downward stroke substantially in synchronism with the rate of travel of the carrier, starting just a trifle ahead of the carrier so that the latter has a small bight of loose yarn to draw upon instead of the entire length which was drawn from the spool and which, if freed at one time, might twist and snarl.

The means for oscillating the arm 4 is a cam 8 on the main cam shaft 9 of the knitting machine. Said cam is so shaped as to give the differential motion to the arm 4 on its pulling stroke and its feeding stroke. Said cam controls the movement of an oscillating lever l which is pivoted at H to the frame of the machine and has its free end connected by a pitman l2 to a lever I 3 fixed to the shaft 5. I

Since the invention contemplates a knitting pattern which involves the change-over from a basic yarn to the special yarn and back again, the control of the lever in by the cam 8 is indirect.

By referring to Figures 2 and 3 a second carrier [4 will be observed for carrying the basic yarn, this being in general only one of several carriers as is suggested by the plurality of carrier rods l5 shown in these figures. The carriers are of conventional construction and conventionally operated. There is the usual pattern cam l6 having the elevations l1 and depressions l8 which determine the period of operation for each of the carriers shown. The carrier operator shaft l9 has a bell crank 20 at the end with a roller 2| which is resiliently pressed against the pattern cam. As shown, with the roller 2| in one of the depressions 18, the carrier l4 which feeds the basic thread to the needle is in operation. When the pattern cam I 6 has rotated to the point where the roller 2| rides upon one of the elevations H, the carrier-operating mechanism will have shifted to the carrier 2 which carries the special yarn. It will be understood of course that the carrier operator mechanism slides back and forth upon the operator shaft l9 through a distance equal to the range of the carriers. The number of courses knit while the roller is either in the depression l8 or upon the elevation I! of the pattern cam I5 is controlled by the pawl 22 and-ratchet 23 which advanced the pattern cam step by step, one step for each traverse of the carrier across the needle bar, that is to say, one step for each course of the knitting.

It will now be clearly understood that when the carrier l4 carrying the normal or basic yarn .is in operation, the arm 4 should be inactive, but that while the carrier 2 is operating the arm 4 should make a complete oscillation for every passage of the carrier across the needle bar. Therefore the lever l 0 will be inactive when the carrier I4 is operating. This is accomplished by means of a circular run-way 24 alongside of the cam 8 and preferably integral therewith and a roller 25 capable of shifting from the circular runway to the cam 8 from which it will be inferred that said circular runway and said cam are tangent to a common plane at the point where this shift occurs. The roller 25 supports a bracket 26 underlying the lever l0 and engaging said arm.

.When the roller is.on the circular runway the The means for shifting the roller 25 from the circular runway 24 to the cam 8 is as follows: A link 21 is pivotally attached at one end to the lower arm 28 of the bell crank lever 20 and at the other to one end of a rocking lever 29 which as shown is pivoted on a horizontal axis 30. The opposite end of said lever 29 rocks against the arm 3| of a bell crank 32 also mounted upon a horizontal axis, the opposite limb of which has a retaining lug 33 which embraces, with lost motion, the extended end portion 34 of a rocking lever 35 mounted on a vertical axis 36. The opposite end of the last named rocking lever has an extension 31 which terminates in a vertical guide 38 for the bracket 25 and roller 25.

The operation of this shifting mechanism is as follows: When the elevation ll of the pattern cam I 6 lifts the roller 2|, it oscillates the bell crank 20 pulls on the link 21 rocks the free end of the rocking lever 29 downward, tips the bell crank 32 to the leftward as viewed in Figure 3,

swinging the rocking lever 35 in a counter-clockwise direction so that the extension 31 moves to the right as viewed in Figure 3 shifting the'roller from the circular runway 24 to the cam 8. When the pattern cam l6 has moved to a position in which the roller 2| falls into the depression [8, the bell crank swings downwardly lifting the rocking lever 29 from the bell crank 32. A spring 39 normally pulls the roller 25 back upon the circular runway 24.

It will be understood that the specific nature of the train of mechanism between thebell crank 20 and the roller 25 is merely illustrative and capable of being replaced by equivalent substituents without transcending the scope of the invention.

Before proceeding with a description in detail of the means for producing drop stitches in the progress of the knitting, it will be understood that the conventional full fashioned hosiery knitting machine is provided with a set of transfer points above the needle bar, usually one for every other needle and cooperating therewith in the narrowing operation. In the normal knit ting of the basic fabric of the stocking the trans fer points are in an elevated inactive position .out of reach of the needles, the latter operating at a low level. When the point is reached for a narrowing operation the transfer points come down and the needles rise to a level at which the transfer points and needles cooperate to effect the transfer of the loop carried by the needle to the transfer point.. The transfer points then go up while the needles descend, the loops being then on the transfer points entirely disassociated with the needles. The transfer points then move laterally a distance of a needle and descend while the needles rise, so as to cooperate with the adjacent needles placing the loops which they carry below the beards of the needles with which they cooperate. The needles then descend, taking the transferred loop while the transfer points go up to their normal inactive position.

In order to drop a stitch it is only necessary to provide that the needle shall not be in position to receive the loop when the transfer point sheds it and this can be accomplished by keeping the needles at the time of the attempted transfer at their low normal working level.

Referring now to Figures 4 and 5, the numeral 40 represents the working cam on the main cam be made integral with the working cam. The arm 42 of the bell crank lever 43 which operates the needle bar 44 has a yoke- 45 at its lower end in which is journalled a roller 46 adapted normally to bear against the surface of the workin cam, and upon occasion to be brought to bear upon the surface of the narrowing cam. There is also a cam 41 on the cam shaft 9 which effects the downward movement of the normally inactive tranfer points 48, Figure 5, to bring them into cooperation with the needles as illustrated in .Figure 7. Transition from normal knitting to narrowing is effected by longitudinal shifting of the cam shaft 9 through means not shown. The working cam 40 is necessarily flush with the narrowing cam in one place, the region 49, see Figure to permit the roller 46 to slide from one cam to the other. At all other points, save one, the working cam is lower than the narrowing cam, that one point being the region 50 of the working cam which projects beyond the narrowing cam, the latter having a relatively low and flattened portion 5| at that point. The elevations 52 and 53 at the opposite sides of the narrowing cam represent low positions of the needle bar while the flat portion 5| of the narrowing cam represents the elevated position of the needle bar at which transfer of the loop from the needle to the transfer point begins to take place as shown in Figure 7 in which needle position, the transfer point 48 is in its lowered position.

The present invention contemplates providing an independent shift of the roller 46 within the yoke 45 so that when it is desired to form drop stitches the roller can be shifted to a position mid-Way between the two cams so that it rides upon the narrowing cam wherever the narrowing cam is larger than the working cam, but when it reaches the region 50 where the throw of the working cam exceeds that of the narrowing cam it then rides upon the working cam. Thus instead of the needle bar moving to a high'level in response to the fiat portion 5| of the narrowing cam it moves to its low working level where it is out of reach of the transfer point. This of course interrupts the transfer so that when the transfer point moves upward, the needle is not there to receive the shed loop.

In carrying out the present invention, the normal construction of the full fashioned knitting machine is slightly altered by providing room within the yoke 45 for the roller 46 to slide along its axis sufficiently to ride mid-way between the working and narrowing cams. An operating yoke 54 straddles the rviler 46, said yoke being fixed to a rod 55 which passes through a fixed bearing 56, the extending end of said rod having a spring 51 adjustably retained by a nut 58, the purpose of which spring is normally to keep the roller over to the left hand side of the yoke 45 as viewed in Figure 4. When the yoke is in this position, the full fashioned knitting machine performs its normal functions of knitting and narrowing without in any Way being affected by the presence of the drop stitch mechanism. The roller 46 is shifted to its middle or drop stitch position by means of a lever 59 which is pivoted at one end around both a horizontal axis 60 and a vertical axis 6|. butts against a stop 62 on the rod 55 and moves the roller 46 to its mid position with respect to the working and narrowing cams. This lever has a roller 63 which is engaged by a swell 64 on the cam 65 mounted on the cam shaft 9. When the swell 64 engages the roller 63, the lever pushescams 40 and 4|.

which abuts against a lug 18 limiting the move- 5 Said lever when actuated,-

against the stop 62 moving the rod 55 in opposition to the tension of the spring 51 placing the roller 46 over the plane of division between the The lever 59 has a stop 11 ment of the lever in the opposite direction and establishing a normal inactive position for th lever 59.

Inasmuch as it is the intention of the present invention to provide a machine which shall make drop stitches at various places as desired, according to different patterns, the swell 64 is made to cover a very small angle of displacement of the cam 65 so that it does not directly control the duration of the period in which the roller 46 'stays in mid-position, but merely places said roller and the appurtenant parts which move with it in position to be taken in charge by said control means.

The latter means may consist fundamentally of a pattern chain 66 of usual construction capable of having the actuating lugs 61 attached to it at any desired intervals and in such arrangement as to give the desired pattern as regards the placing of the drop stitching. A bell crank lever 68 is suitably mounted as upon the support 69, on. a horizontal axis, the arm 18 of said lever lying in the path of the lugs 61 to be elevated thereby. The opposite arm II of said bell crank lever has a downwardly bent end I2 formed with a rabbet 13 facing away from the spring 51. The rod 55 has a stop 14 adapted to be engaged in said rabbet when said bell crank lever is rocked through the engagement of one of the lugs 61 on the pattern chain with the arm 10. The stop 14 5 is at such a point on the rod 55 as will bring the stop just a slight distance in front of the rabbet I3 when the rod is moved forward against the tension of the spring 51 by the lever 59.

The operation of the pattern chain is so synchronized with the movement of the lever 59 that if a drop stitch is to be made a lug 61 on the pattern chain tilts the bell crank 68 while the rod 55 is in its advance position, permitting the downwardly bent portion 12 of the bell crank to move behind the stop 14 which catches in the rabbet when the lever 59 returns under the pull of the spring 15 holding the roller 46in its mid position. The pattern chain is advancedstep by step by means of a pawl and ratchet 16 suitably opero ated by means which is conventional and therefore not necessary to be shown. A single one of the lugs 61 will dwell under the bell crank lever 68 for only one step of movement of the pattern chain. This means only one drop stitch for each revolution of. the cam shaft 9.

In the preceding description it was stated that in general the number of transfer points is onehalf the number of needles. This refers of course to only one specific pattern. The number of transfer needles may of course be reduced as desired. for example, one for every fourth needle so that isolated drop stitches or rows of drop stitches may be made at spaced intervals around the stocking.

- In knitting, the sequence of operations will generally be as follows: A certain number of courses of plain stitches will be knit employing the working cam 48. Then preparatory to the drop stitching, the cam shaft 9 will be shifted to bring the 70 be shifted to" bring the roller" on to the working 'cal surface 80 which is between said cams.

cam and so many working courses will be laid as to determine the length of the rows of drop stitching. Then the cam shaft 9 will again be shifted to bring the roller 46 over the narrowing cam and the lever 59 will at the same time shift the roller 46 so that it overlies both cams. Then when the roller 46 rides upon the elevated region 50 of the working cam, the loops of the last working course which were transferred to the narrowing points during that part of the normal narrowing operation of the narrowing cam 4| will be shed into the air by the narrowing points, whereupon the elasticity of the yarn will run out all the loops in the knitting above this shed loop until the picot stitch is reached or if the elasticity of the yarn is not sufficient, the loops may be run out by hand.

It is evident that the swell 64 of the cam 65 engages the roller 63 and moves the lever 59 laterally once for every revolution of the cam shaft 9. The cam 65 is so positioned on the cam shaft that the lever 59 reaches its limit of movement slightly in advance of the shifting of the cam shaft to either working or narrowing position. With the cam shaft in working position, the cam 65 will actuate the lever 59 to position the roller 46 exactly midway over both the working and narrowing cams. After these parts have reached their limit of movement, shifting of the cam shaft to narrowing position would cause further movement of the lever 59 and tend to break the mechanism unless some means were employed to move the lever 59 from the path of the cam 65.

With this end in view, the cam shaft 9 is provided with an auxiliary cam '19 and a cylindrical surface 80. The auxiliary cam 19 and the surface 80 may, if desired, be an integral part of the cam 65. A bracket 8| is fixed to the lever 59 and overhangs the cams 85 and I9 and the cylindri- Said bracket is provided with ears 82 and 83 forming bearings for a pin 84 upon which a roller 85 is mounted. Said roller is approximately twice the width of the cam 19 to insure its contact with said cam in both working and narrowing positions of the cam shaft 9.

The swell of the cam 19 is positioned so as to engage the roller 85 at the time the cam 65 has moved the lever 59 to its maximum outward lateral position and the cam shaft 9 is beginning to shift. The roller 85 will ride upon the swell of the cam 19 raising the lever 59 vertically out of the path of the cam 65, preventing further lateral movement of the lever 59 during the shifting of the cam shaft to narrowing position.

Thus, it will be seen that the lever 59 has two movements during each revolution of the cam shaft, first laterally and then vertically. As both of these movements take place while the roller 46 passes over that part of the working and narrowing cams which are flush with each other, springs and 51 will return the parts to their normal inoperative positions before roller 46 starts to impart motion to the needle bar. The machine therefore will operate in its normal manner unless a lug 61 passes under the arm 10 of the lever 68 looking the roller 46 in its shifted position.

While we have in the above description disclosed what we believe to be a preferred and practical form of the invention, it will be understood to those skilled in the art that the details of constructions as illustrated and described are by way of example and not to be construed as limiting the scope of the invention which is defined in the appended claims.

What we claim is:

1. In a flat knitting machine including an axially shiftable cam shaft having the conventional narrowing cam and working cam in side by side relation, a needle bar, transfer points, a cam on said cam shaft for raising and lowering said transfer points, a lever for operating said needle bar, a roller for engaging said narrowing and said working cam, said roller being axially slidable in said lever, means for biasing said roller into a normal position with respect to said lever, and means for shifting said roller so that it occupies a mid position intersected by the plane of division between said narrowing and working cams while said cam shaft is in its narrowing position, whereby said roller riding upon the projecting portion of said working cam during that phase of the narrowing movement when the needle bar would ordinarily be elevated, lowers said needle bar below the transfer level of the transfer points producing a drop stitch.

2. In a flat knitting machine, including an axially shiftable cam shaft having the conventional narrowing cam and working cam in side by side relation, a needle bar, transfer points, a cam on said cam shaft for raising and lowering said transfer points, a lever for operating said needle bar, a roller for engaging said narrowing cam and said working cam, said roller being slidable in said lever, means for biasing said roller in a normal position with respect to said lever, means for momentarily shifting said roller so that it occupies a mid position intersected by the planes of division between the narrowing and working cams, once on every revolution of said cam shaft, said means being so positioned as to produce said momentary shift of said roller before the latter reaches that phase of said working and narrowing cams in which said working cam projects beyond said narrowing cam, and means actuated by a pattern chain for holding said roller in said mid position, after it has been shifted into said position by said shifting means whereby said roller riding upon the projecting portion of the working cam during the phase of the narrowing movement when the needle bar would ordinarily be elevated, lowers the needle bar below the level of the transfer points, dropping the stitches.

3. In a fiat knitting machine including an axially shiftable cam shaft having the conventional narrowing cam and working cam in side by side relation, a needle bar, transfer points, a cam on said cam shaft for raising and lowering said transfer points, a lever for operating said needle bar, a roller for engaging said narrowing cam and said working cam, said roller being slidable in an eye in said lever, a yoke freely embracing said roller, a rod for moving said yoke and roller in an axial direction, a spring for normally biasing said rod, yoke and roller in a position in which said roller is intersected by the plane of division between said narrowing and Working cams while said cam shaft is in its narrowing position, a stop on said rod, a laterally swinging lever engageable with said stop for moving said rod in opposition to said spring to bring said roller to its midposition with respect to said narrowing and working cams, a lever-actuating cam of small circumferential amplitude for rocking said swinging lever against said stop for momentarily shifting said roller to midposition with respect to said narrowing and working cams, said leveractuating cam being so displaced as to complete the momentary shifting of said roller before it reaches the point at which the working cam projects beyond the narrowing cam, and means actuated by a pattern chain for engaging a stop on said rod while the roller is in midposition for holding said roller in said midposition whereby said roller arriving upon the projecting portion i of the working cam during that phase of the narrowing movement when the needle bar would ordinarily be elevated, lowers the needle bar below the transfer level of the transfer points forming drop stitches.

4. In a flat knitting machine including the usual needle bar actuating lever and the unitarily revoluble narrowing and working cams selectively cooperable with said lever, drop stitch mechanism comprising means for making said lever responsive to the successive dominant elevations of both said cams during the same revolution of the cam shaft whereby the needle bar shall be in its normal working position and away from the loop transfer level when the normal loop shedding function of the narrowing operation takes place.

5. In a flat knitting machine including the usual needle bar actuating lever and the cam shaft carrying the unitarily revoluble narrowing and working cams selectively cooperable with said lever upon axial shifting of said cam shaft, drop the successive dominant elevations of both said cams during the same revolution of the cam shaft whereby the needle bar shall be in its normal working position and away from the loop transfer level when the normal loop-shedding function of the narrowing operation takes place.

6. In a fiat knitting machine including the usual needle bar actuating lever and the cam shaft carrying the unitarily revoluble narrowing and working cams selectively cooperable with said lever upon axial shifting of said cam shaft, drop stitch mechanism comprising means for moving an element of said lever which contacts said cams to a midposition with respect to the plane of division between said cams, pattern chain controlled means for maintaining said lever element in said midposition, making said lever responsive to the successive dominant elevations of both said cams whereby the needle bar shall be in its normal working position and away from the loop transfer level when the normal loop shedding function of the narrowing operation takes place.

'7. A fiat knitting machine as claimed in claim 3 including a cam on said cam shaft and movable therewith cooperating with means on said swinging lever for raising the latter out of the path of Y 

